Bandwidth available for transmission of information in a communications network is constrained by the limits of the equipment used to transmit and receive information carrier signals and the physical properties of the media over which the carrier signals are transmitted. For example, the bandwidth available for through-the-air data signal transmission is a function of the frequency of the carrier signal. It is well known that the bandwidth available for through-the-air signal transmission, which is typically performed at radio frequencies, is much less than that available for signal transmission on other media, such as optical fiber.
In a communications network, oftentimes many applications, which are used to generate messages containing, for example, text files or streaming video, for transfer over the network and are installed at various respective network communications devices, such as computers having network communications capabilities, attempt to transmit messages over the network simultaneously and, therefore, compete for the fixed available bandwidth of a network access point. Many network protocols, including the commonly used Internet Protocol (“IP”), do not regulate bandwidth use by any application, such that a message transmission from an application consumes as much of the available bandwidth as the application can obtain. Consequently, once an application is granted access to the communications network, an application can and often does use more bandwidth than it needs for effective operation, and uses such bandwidth until a message transmission is completed.
Some prior art networks regulate bandwidth usage by pre-allocating predetermined bandwidths to respective applications. For example, prior art communications network systems on aircraft carriers pre-allocate fixed bandwidths to respective network applications whose bandwidth operating requirements can be fixed or variable. The network applications are coupled to a network access point, which has a predetermined available bandwidth and through which through-the-air communication links between the communications system on the aircraft carrier and a remote a communications site are established. As fixed bandwidths are pre-allocated to the respective applications, the bandwidth pre-allocated to one application is not available for use by any other application, even when the one application is not using a portion or all of the pre-allocated bandwidth. Consequently, in such networks, the total bandwidth that the applications of the network require or use oftentimes exceeds the available bandwidth at the access point.
In addition, when competition for bandwidth between and among applications is not regulated, messages containing time sensitive or high priority information may not be delivered promptly to a destination communications device because of a lack of available bandwidth. For example, applications in a network often simultaneously attempt to transmit low priority data, such as power point or text files; medium priority data, such as streaming video which does not transmit properly if sufficient bandwidth is not allocated; and also high priority, time critical data. If the bandwidth allocation in the network is unmanaged, such that the aggregate message traffic exceeds the total bandwidth capacity at an access point, low and medium priority data can compete with the time critical data and cause the time critical data to experience undue delay.
Although prior art network communications data flow control devices, such as sold under the brand names Packeteer's PacketShaper™ or Sitara Network's QoSWorks™, recognize messages based on IP header information included with the message and allocate bandwidth accordingly based on the recognized message, the flow control devices do not allocate bandwidth with regard to the application that is the source of the message, the actual priority of a message from a first application relative to the priorities of other messages from other respective applications simultaneously vying for bandwidth or the reasons why a user of an application transmitted a particular message.
In addition, prior art communications networks do not provide real time information concerning actual, and changes in actual, use of the available bandwidth of an access point by the various applications in the network. Therefore, a user of an application or a network operator cannot plan transmission of a message from, or dynamically modify bandwidth allocation or relative priority for, a selected application according to real time changes in bandwidth usage or operational situations. For example, a user of an application on an aircraft carrier may be unaware of changes in an operational situation on the carrier which should result in the user not attempting to transmit medium priority messages, such as streaming video data, through the network to avoid occupying a portion of the available bandwidth of an access point.
Therefore, a need exists for method and system for automated monitoring and control of the allocation of network bandwidth to applications of a communications network, where bandwidth constraints and relative priorities can be assigned to respective applications in real time at a graphical user interface (“GUI”) and where the GUI displays, using operational terms common to the overall enterprise in which and for which the network is implemented, the bandwidth constraints, relative priorities and other information constituting a selected bandwidth allocation strategy, inputs for modifying the strategy, actual bandwidth use at an access point and estimates of message transfer delays for applications of the selected strategy which are computed based on the actual bandwidth use at the access point.